# symbol Specification Sheet

Computer Algebra Kit (c) 1993,00 by Comp.Alg.Objects. All Rights Reserved.

# Symbol

Inherits from: CAObject

## Class Description

Maturity Index : Relatively Mature

For symbols created with the factory method str:, the first character of the str of the symbol object must be a letter. Subsequent characters can be letters or digits. Whitespace or control characters are not allowed.

Using the factory method chars:count:, it's possible to use arbitrary C strings as the value of the symbol; in this case Symbol just acts like a regular Objective C String class. If you intend to use the object as a mathematical symbol, it's not advised to do this as you might incorrectly interpret spaces etc. as mathematical operators.

## Methods

### str:

+str:(STR)aString
Creates a new symbol, and sets its value to a copy of aString. Returns nil if aString is not suited as value for a symbol (when the first letter is not a letter, for instance).

### chars:count:

+chars:(STR)aBuffercount:(int)numChars
Creates a new symbol, and sets its value to a copy of the first numChars characters of aBuffer. For this method, there are no restrictions on the C string being used.

### copy

-copy
Returns a new symbol object. Copies the string.

### deepCopy

-deepCopy
Equivalent to copy.

### release

-release
Frees the memory for the string value.

### str

- (STR)str
Returns the string value of the symbol. The first character is a letter, subsequent characters can be alphanumeric.

### str:

-str:(STR)aString
Creates a new symbol, and sets its value to a copy of aString. Returns nil if aString is not suited as value for a symbol.

### hash

- (unsigned)hash
Returns a hash value based upon the string.

### isEqual:

- (BOOL)isEqual:b
Returns YES if the str's of both objects are equal.

### compare:

- (int)compare:b
Compares the str's of both objects.

### isLetter

- (BOOL)isLetter
Whether the symbol consists of just one character (and hence, is a letter, not a digit).

### printOn:

-printOn:(IOD)aFile
Prints the symbol to aFile.